Writer won't enter master mode

My book has 30 chapters in a Master Document. Recently reloaded latest LO to a new SSD. Now I can’t enter Master Mode in Navigator only Content Navigation View. How can I fix this?
This document has worked correctly for over 2 years. It appears that is the problem. LO obviously knows it is a master doc but Navigator doesn’t. This is a definite killer BUG since I can’t add chapters to my new book.

Version: (x64) / LibreOffice Community
Build ID: f6099ecf3d29644b5008cc8f48f42f4a40986e4c
CPU threads: 4; OS: Windows 10.0 Build 19042; UI render: Skia/Raster; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: CL

Someone please tell me when this BUG is fixed.

This place is for finding solutions within the existing incarnations of the LibreOffice suite. You already did that, and posted your solution. No further action is to be expected.

To report a bug for fixing in future incarnations, use bugzilla. You should then receive feedback when issue is handled.

Bugzilla bug 140397 submitted. Issue identified by developers and fix in the works. DON’T USE IF YOU USE MASTER DOCUMENTS. It is defective. Use until a new version of 7.1 is released.

Deleted and reloaded Problem fixed.
7.0.4 Navigator has 2 buttons. The top one is for Master and the bottom one is for Content. In 7.1 there is 1 button with up-down arrows positioned in the Content location. The Master button was deleted. The probable intent was to go back to a single toggle button as in earlier versions but the code driving the buttons was not updated properly so it selects Content/Content/Content/Content/…
Someone please tell me when this BUG is fixed. Until then use 7.0.4 if you have a master document.

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